merge: sidebar-cards base into 112-detail-render

Dead status can be observed before the settle step's store write
lands, so the test's store read raced the write under parallel load.
Wait for the store to have the entry before asserting on it, same as
the settle-state wait a few lines below.

Fixes #111

crates/maestro-daemon/tests/session_manager.rs

@@ -769,6 +769,14 @@ async fn natural_exit_of_a_guarded_worktree_retains_it_in_the_store() {
         "a dirty worktree must be retained on natural exit"
     );
     // ...in the store, under the exit reason.
+    // (`Dead` is observable a moment before the settle step's store write lands.)
+    wait_for_async(Duration::from_secs(3), || async {
+        fx.retained_store()
+            .load_all()
+            .map(|all| all.len() == 1)
+            .unwrap_or(false)
+    })
+    .await;
     let all = fx.retained_store().load_all().expect("load_all");
     assert_eq!(all.len(), 1);
     assert_eq!(all[0].path, wt_path);

crates/maestro-protocol/src/lib.rs

@@ -123,7 +123,12 @@ pub enum SessionStatus {
 /// Inferred session activity, orthogonal to [`SessionStatus`] (NAP-340). The
 /// daemon derives this from tmux pane state, PTY quiescence, and `/proc`
 /// inspection — never by parsing the terminal byte stream.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default)]
+///
+/// Deserializes leniently (#110, SIDEBAR.md Precedence): an unknown variant
+/// from a newer daemon becomes [`ActivityState::Idle`] instead of failing the
+/// whole `Session`. Non-string values still error — only variant names are
+/// forgiven.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Default)]
 pub enum ActivityState {
     /// Producing output, or the foreground process is busy.
     Active,
@@ -137,11 +142,34 @@ pub enum ActivityState {
     Error,
 }
 
+impl<'de> Deserialize<'de> for ActivityState {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let s = String::deserialize(deserializer)?;
+        Ok(match s.as_str() {
+            "Active" => Self::Active,
+            "AwaitingInput" => Self::AwaitingInput,
+            "Error" => Self::Error,
+            // Known or not, any other spelling degrades to the neutral default
+            _ => Self::Idle,
+        })
+    }
+}
+
 /// HTTP `POST /api/sessions/:id/activity` body (#105): an agent's report of
 /// its own state. The daemon holds the reported state above its own inference
 /// for a fixed TTL, then resumes inference.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct ReportActivityRequest {
+    /// Parsed strictly, unlike [`ActivityState`]'s own lenient `Deserialize`
+    /// (#110). Leniency exists so a client reading a *newer* daemon's snapshot
+    /// degrades an unrecognised state to `Idle` instead of dropping the whole
+    /// session. A report travelling the other way has no such excuse: an agent
+    /// posting a state this daemon does not know is a bug in the agent, and
+    /// silently recording it as `Idle` would hide that behind a 204.
+    #[serde(deserialize_with = "strict_activity_state")]
     pub state: ActivityState,
     /// Short human string shown next to the state (e.g. an error message).
     /// The daemon caps its length server-side.
@@ -149,6 +177,26 @@ pub struct ReportActivityRequest {
     pub detail: Option<String>,
 }
 
+/// Reject an unknown [`ActivityState`] spelling instead of degrading it to
+/// `Idle`. Used only by [`ReportActivityRequest`]; see the note there.
+fn strict_activity_state<'de, D>(deserializer: D) -> Result<ActivityState, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    use serde::de::Error as _;
+    let s = String::deserialize(deserializer)?;
+    match s.as_str() {
+        "Active" => Ok(ActivityState::Active),
+        "Idle" => Ok(ActivityState::Idle),
+        "AwaitingInput" => Ok(ActivityState::AwaitingInput),
+        "Error" => Ok(ActivityState::Error),
+        other => Err(D::Error::unknown_variant(
+            other,
+            &["Active", "Idle", "AwaitingInput", "Error"],
+        )),
+    }
+}
+
 /// Optional worktree request attached to a `CreateSessionRequest`.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct WorktreeSpec {
@@ -658,6 +706,35 @@ mod tests {
         assert_eq!(ActivityState::default(), ActivityState::Idle);
     }
 
+    // #110 / SIDEBAR.md Precedence: a future daemon may send an
+    // `ActivityState` variant this client does not know; it must degrade to
+    // the neutral default instead of failing the whole `Session`.
+    #[test]
+    fn unknown_activity_state_variant_deserializes_to_idle() {
+        assert_eq!(
+            serde_json::from_value::<ActivityState>(serde_json::json!("Teleported")).unwrap(),
+            ActivityState::Idle
+        );
+
+        let mut future = serde_json::to_value(sample_session()).unwrap();
+        future["activity"] = serde_json::json!("QuantumEntangled");
+        let s: Session = serde_json::from_value(future).unwrap();
+        assert_eq!(s.activity, ActivityState::Idle);
+    }
+
+    #[test]
+    fn non_string_activity_payload_still_fails_deserialization() {
+        let json = serde_json::json!({
+            "id": Uuid::from_u128(1),
+            "cwd": "/tmp",
+            "command": "bash",
+            "status": "Running",
+            "created_at": "2026-05-24T12:00:00Z",
+            "activity": 42,
+        });
+        assert!(serde_json::from_value::<Session>(json).is_err());
+    }
+
     #[test]
     fn activity_detail_defaults_to_none_on_legacy_payload() {
         // #105: a daemon predating the detail field omits it; it must

crates/maestro-tui/src/sidebar.rs

@@ -160,12 +160,26 @@ impl Sidebar {
             spans.push(Span::styled(" ", base));
             spans.push(Span::styled(format_state_duration(d), dot_style));
         }
+        // The trailing fragments are measured up front so a long detail
+        // truncates ahead of them instead of pushing them off the line
+        // (docs/SIDEBAR.md).
+        let mut tail: Vec<Span<'static>> = Vec::new();
         if let Some(b) = blocked {
-            spans.push(Span::styled(format!(" ⚠ {b}"), muted));
+            tail.push(Span::styled(format!(" ⚠ {b}"), muted));
         }
         if dead {
-            spans.push(Span::styled(" exited", muted));
+            tail.push(Span::styled(" exited", muted));
         }
+        if let Some(detail) = s.activity_detail.as_deref().filter(|d| !d.is_empty()) {
+            let head_w: usize = spans.iter().map(|sp| sp.width()).sum();
+            let tail_w: usize = tail.iter().map(|sp| sp.width()).sum();
+            let budget = width.saturating_sub(head_w + tail_w);
+            spans.extend(fit_to_width(
+                vec![Span::styled(format!(" {detail}"), muted)],
+                budget,
+            ));
+        }
+        spans.extend(tail);
         Some(fit_to_width(spans, width))
     }
 }
@@ -531,6 +545,93 @@ mod tests {
         );
     }
 
+    /// #112: the agent-reported detail sits right after the duration on the
+    /// meta line, in the muted style (docs/SIDEBAR.md).
+    #[test]
+    fn errored_session_shows_its_reported_detail_on_the_meta_line() {
+        let mut s = session_named(1, "claude");
+        s.activity = ActivityState::Error;
+        s.activity_since = Utc::now() - Duration::seconds(90);
+        s.activity_detail = Some("cargo build failed".into());
+        let sb = Sidebar {
+            sessions: vec![s],
+            highlight: None,
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 40, 8));
+        let idx = all.iter().position(|l| l.contains("claude")).unwrap();
+        let meta = &all[idx + 1];
+        assert!(meta.contains('●'), "meta line carries the dot: {meta:?}");
+        assert!(
+            meta.contains("1m"),
+            "duration precedes the detail: {meta:?}"
+        );
+        assert!(
+            meta.contains("cargo build failed"),
+            "reported detail must render: {meta:?}"
+        );
+    }
+
+    /// A fresh Error report earns line 2 on its own (contract rule 4), with
+    /// the detail even though no duration has accrued.
+    #[test]
+    fn fresh_errored_session_earns_a_meta_line_for_its_detail() {
+        let mut s = session_named(1, "claude");
+        s.activity = ActivityState::Error;
+        s.activity_since = Utc::now() - Duration::seconds(5);
+        s.activity_detail = Some("waiting for approval".into());
+        let sb = Sidebar {
+            sessions: vec![s],
+            highlight: None,
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 40, 8));
+        let idx = all.iter().position(|l| l.contains("claude")).unwrap();
+        assert!(
+            all[idx + 1].contains("waiting for approval"),
+            "detail must render on a fresh report's own meta line: {:?}",
+            all[idx + 1]
+        );
+    }
+
+    /// #112 via docs/SIDEBAR.md: the detail truncates with `…` ahead of the
+    /// trailing fragments — a long detail never pushes blocked work or
+    /// `exited` off the line, and never wraps.
+    #[test]
+    fn long_detail_yields_to_blocked_work_and_exited() {
+        let mut s = session_named(1, "claude");
+        s.status = SessionStatus::Dead;
+        s.activity_since = Utc::now() - Duration::seconds(5);
+        s.activity_detail =
+            Some("an absurdly long error message that cannot possibly fit ".repeat(3));
+        s.blocked_work = Some(InTheWay {
+            unpushed_commits: 2,
+            ..InTheWay::default()
+        });
+        let sb = Sidebar {
+            sessions: vec![s],
+            highlight: None,
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 40, 8));
+        let idx = all.iter().position(|l| l.contains("claude")).unwrap();
+        let meta = content(&all[idx + 1]);
+        assert!(meta.contains('…'), "truncated detail ends with …: {meta:?}");
+        assert!(
+            meta.contains("2 unpushed commits"),
+            "blocked work stays on the line: {meta:?}"
+        );
+        assert!(
+            meta.contains("exited"),
+            "exited fragment stays on the line: {meta:?}"
+        );
+        assert!(
+            content(&all[idx + 2]).trim().is_empty(),
+            "meta line must not wrap: {:?}",
+            all[idx + 2]
+        );
+    }
+
     /// docs/SIDEBAR.md: a payload predating #102 carries an epoch
     /// `activity_since` and so contributes no duration — a card must not claim
     /// the session has been idle since 1970. The dot still renders when some

docs/SIDEBAR.md

@@ -55,7 +55,10 @@ only when their trigger holds. A payload that predates #102 (no usable
 `<detail>` is an agent-reported string (#105) — e.g. why a session is in
 `Error`. It sits right after the duration, in the muted style, and shows only
 while an agent-reported state is in force (see Precedence): when the report
-lapses at its TTL or is replaced, the detail goes with it.
+lapses at its TTL or is replaced, the detail goes with it. The detail
+truncates with `…` ahead of the trailing fragments — a long detail never
+pushes `<blocked work>`, `exited`, or `<command>` off the line, and neither
+client ever lets it wrap.
 
 `<command>` is optional and muted: the session's command line, shown only when
 the rendered name came from `metadata.name` and differs from the command (the
@@ -108,3 +111,9 @@ If a client receives an `ActivityState` variant it does not know, it must not
 fail rendering: treat it as `Idle` (neutral/dim, line-2 rules apply as usual)
 until the daemon sends a variant it does know. Rust clients deserialize
 activity leniently for the same reason.
+
+Leniency runs one way only. It covers a client *reading* a newer daemon, where
+dropping the whole session would be worse than dimming one card. A report
+arriving at `POST /api/sessions/:id/activity` is parsed strictly and an unknown
+state is a 4xx: an agent posting a state the daemon does not know is a bug in
+the agent, and answering 204 would hide it.

web/src/catalog.test.ts

@@ -105,6 +105,38 @@ describe("blocked-work indicator (#83)", () => {
   });
 });
 
+describe("agent-reported detail (#112)", () => {
+  const ago = (ms: number): string => new Date(Date.now() - ms).toISOString();
+
+  it("renders the reported detail right after the duration on line 2", () => {
+    const s = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000020",
+      status: "Dead",
+      activity: "Error",
+      activity_since: ago(90_000),
+      activity_detail: "cargo build failed",
+    });
+    const el = renderSidebar(storeWith([s])).el;
+    const line2 = rowFor(el, s.id)?.querySelector<HTMLElement>(".card-line2");
+    expect(line2?.querySelector(".activity-detail")?.textContent).toBe("cargo build failed");
+    const order = [...line2!.children].map((c) => c.className);
+    expect(order.indexOf("activity-detail")).toBeGreaterThan(order.indexOf("activity-duration"));
+    expect(order.indexOf("activity-detail")).toBeLessThan(
+      order.findIndex((c) => c.startsWith("card-flag")),
+    );
+  });
+
+  it("omits the detail when no report is in force", () => {
+    const s = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000021",
+      activity: "Active",
+      activity_since: ago(90_000),
+    });
+    const el = renderSidebar(storeWith([s])).el;
+    expect(rowFor(el, s.id)?.querySelector(".activity-detail")).toBeNull();
+  });
+});
+
 describe("session cards (#107)", () => {
   const ago = (ms: number): string => new Date(Date.now() - ms).toISOString();
 

web/src/catalog.ts

@@ -42,6 +42,9 @@ function metaLine(s: Session, now: number): string {
   const fragments = [
     `<span class="activity-dot" role="img" title="${escapeHtml(stateWord)}" aria-label="${escapeHtml(stateWord)}"></span>`,
     duration ? `<span class="activity-duration">${duration}</span>` : "",
+    s.activity_detail
+      ? `<span class="activity-detail">${escapeHtml(s.activity_detail)}</span>`
+      : "",
     blockers
       ? `<span class="card-flag leaf-blocked" title="Kill will be refused unless forced">⚠ ${escapeHtml(formatInTheWay(blockers))}</span>`
       : "",

web/src/styles.css

@@ -851,6 +851,17 @@ textarea {
   flex: 0 0 auto;
 }
 
+/* Agent-reported detail (#112): sits after the duration, shrinks with an
+   ellipsis so it never pushes the trailing fragments off the line. */
+.activity-detail {
+  color: var(--faint);
+  flex: 0 1 auto;
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
 /* Blocked-work / exited / command fragments recede: the ⚠ glyph already
    signals severity and "exited" dims with the row. */
 .card-flag {